The present invention relates to threading tools for the false-twist spindles of yarn texturing machines and, specifically, to a tool and its use for threading the pin of a spindle having no threading holes or slots.
Today's most common type of a false-twist spindle constitutes a C-shaped fixed housing with a small vertically mounted tubular element capable of rotation at speeds in the order of 500,000 to 600,000 rpm, together with means for transmitting rotational drive to said tubular element or "twist tube." This tube, with its associated twist pin, situated transverse to the axial bore, is itself commonly referred to as a false-twist spindle, and is so designated herein.
In U.S. Pat. No. 3,574,273 the history, characteristics, and particularly the threading problems of the pin type of spindle are discussed in great detail. Threading these spindles requires passing the thread-line up through the tube and taking one or more turns around the twist pin. Since an enclosed pin lying across the diameter of a simple cylinder is essentially inaccessible to threading, the art has resorted to various geometrical modifications of the spindle walls in the vicinity of the pin, notably in the form of notches, grooves, slots and drilled holes. U.S. Pat. No. 3,475,895 shows a simplified threading process which is made possible by the presence of carefully located drilled holes. Left unmentioned therein is the fact that the holes cause a whistling noise when the spindle is spun at high speed. U.S. Pat. No. 3,574,273 concerns itself with the same threading problem as that of applicant, that is, threading in the absence of holes or slots. Each of its two processes, however, suffers from the necessity to cut and tie ech threadline, which operations add greatly to the difficulty and time of performing each threadup. In comparison with this tedious prior method, the ease of using the present tool and process is particularly outstanding, and the tool thus makes it possible to secure the full advantages of quiet-running imperforate spindles on commercial false-twist texturing machines.
The present invention provides a pair of fine-gauge wire tools, one for S- and the other for Z-twist threadup, said tools being mirror images of each other, and a method of applying said tools to the thread-up of pin-type false-twist spindles. Each tool consists of a very fine-gauge but stiff section of wire having an elongated handle end and an opposite end having two bends. The intermediate ben is of comparatively large dimension relative to the bore of the spindle, while the bend at the end is smaller and preferably turned substantially at a right angle to the intermediate bend. The threadup of a yarn end is effected very easily by two pairs of down-and-up motions of the tool and one pair of rotational motions of either the spindle of the tool, without any cutting or tying of the yarn.
It is thus an object of the invention to provide a tool for threading the pin of an imperforate false-twist spindle or twist tube.
It is a further object to provide a rapid and easy method for using said tool to thread said pin.
It is a further object to make it commercially practical to secure the noise-reduction benefits of an imperforate spindle.
The foregoing and other objects and advantages will become apparent on considersation of the following description and accompanying drawings.